Hermetic seals to metals are difficult to maintain under various operating conditions, such as changes in temperature. One approach to form matched seals in metals having a high coefficient of thermal expansion (CTE), for example stainless steel (SS), is the use of high CTE glass-ceramics (GCs). However, mismatches in thermal expansion characteristics can result in unsealing between such metal and GC interfaces in a seal. Additional compositions and methods are needed to provide GC compositions that more accurately match the thermal characteristics of metals.